Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libcrypto/bn/bn_ctx.c	Lines:	93	123	75.6 %
Date:	2017-11-07	Branches:	42	62	67.7 %


/* $OpenBSD: bn_ctx.c,v 1.15 2017/01/29 17:49:22 beck Exp $ */
/* Written by Ulf Moeller for the OpenSSL project. */
/* ====================================================================
 * Copyright (c) 1998-2004 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#if !defined(BN_CTX_DEBUG) && !defined(BN_DEBUG)
#ifndef NDEBUG
#define NDEBUG
#endif
#endif

#include <stdio.h>
#include <string.h>

#include <openssl/opensslconf.h>

#include <openssl/err.h>

#include "bn_lcl.h"

/* TODO list
 *
 * 1. Check a bunch of "(words+1)" type hacks in various bignum functions and
 * check they can be safely removed.
 *  - Check +1 and other ugliness in BN_from_montgomery()
 *
 * 2. Consider allowing a BN_new_ex() that, at least, lets you specify an
 * appropriate 'block' size that will be honoured by bn_expand_internal() to
 * prevent piddly little reallocations. OTOH, profiling bignum expansions in
 * BN_CTX doesn't show this to be a big issue.
 */

/* How many bignums are in each "pool item"; */
#define BN_CTX_POOL_SIZE	16
/* The stack frame info is resizing, set a first-time expansion size; */
#define BN_CTX_START_FRAMES	32

/***********/
/* BN_POOL */
/***********/

/* A bundle of bignums that can be linked with other bundles */
typedef struct bignum_pool_item {
	/* The bignum values */
	BIGNUM vals[BN_CTX_POOL_SIZE];
	/* Linked-list admin */
	struct bignum_pool_item *prev, *next;
} BN_POOL_ITEM;

/* A linked-list of bignums grouped in bundles */
typedef struct bignum_pool {
	/* Linked-list admin */
	BN_POOL_ITEM *head, *current, *tail;
	/* Stack depth and allocation size */
	unsigned used, size;
} BN_POOL;

static void		BN_POOL_init(BN_POOL *);
static void		BN_POOL_finish(BN_POOL *);
#ifndef OPENSSL_NO_DEPRECATED
static void		BN_POOL_reset(BN_POOL *);
#endif
static BIGNUM *		BN_POOL_get(BN_POOL *);
static void		BN_POOL_release(BN_POOL *, unsigned int);

/************/
/* BN_STACK */
/************/

/* A wrapper to manage the "stack frames" */
typedef struct bignum_ctx_stack {
	/* Array of indexes into the bignum stack */
	unsigned int *indexes;
	/* Number of stack frames, and the size of the allocated array */
	unsigned int depth, size;
} BN_STACK;

static void		BN_STACK_init(BN_STACK *);
static void		BN_STACK_finish(BN_STACK *);
#ifndef OPENSSL_NO_DEPRECATED
static void		BN_STACK_reset(BN_STACK *);
#endif
static int		BN_STACK_push(BN_STACK *, unsigned int);
static unsigned int	BN_STACK_pop(BN_STACK *);

/**********/
/* BN_CTX */
/**********/

/* The opaque BN_CTX type */
struct bignum_ctx {
	/* The bignum bundles */
	BN_POOL pool;
	/* The "stack frames", if you will */
	BN_STACK stack;
	/* The number of bignums currently assigned */
	unsigned int used;
	/* Depth of stack overflow */
	int err_stack;
	/* Block "gets" until an "end" (compatibility behaviour) */
	int too_many;
};

/* Enable this to find BN_CTX bugs */
#ifdef BN_CTX_DEBUG
static const char *ctxdbg_cur = NULL;

static void
ctxdbg(BN_CTX *ctx)
{
	unsigned int bnidx = 0, fpidx = 0;
	BN_POOL_ITEM *item = ctx->pool.head;
	BN_STACK *stack = &ctx->stack;

	fprintf(stderr, "(%08x): ", (unsigned int)ctx);
	while (bnidx < ctx->used) {
		fprintf(stderr, "%03x ",
		    item->vals[bnidx++ % BN_CTX_POOL_SIZE].dmax);
		if (!(bnidx % BN_CTX_POOL_SIZE))
			item = item->next;
	}
	fprintf(stderr, "\n");
	bnidx = 0;
	fprintf(stderr, "          : ");
	while (fpidx < stack->depth) {
		while (bnidx++ < stack->indexes[fpidx])
			fprintf(stderr, "    ");
		fprintf(stderr, "^^^ ");
		bnidx++;
		fpidx++;
	}
	fprintf(stderr, "\n");
}
#define CTXDBG_ENTRY(str, ctx) \
	do { \
		ctxdbg_cur = (str); \
		fprintf(stderr, "Starting %s\n", ctxdbg_cur); \
		ctxdbg(ctx); \
	} while(0)

#define CTXDBG_EXIT(ctx) \
	do { \
		fprintf(stderr, "Ending %s\n", ctxdbg_cur); \
		ctxdbg(ctx); \
	} while(0)

#define CTXDBG_RET(ctx,ret)
#else
#define CTXDBG_ENTRY(str, ctx)
#define CTXDBG_EXIT(ctx)
#define CTXDBG_RET(ctx,ret)
#endif

/* This function is an evil legacy and should not be used. This implementation
 * is WYSIWYG, though I've done my best. */
#ifndef OPENSSL_NO_DEPRECATED
void
BN_CTX_init(BN_CTX *ctx)
{
	/* Assume the caller obtained the context via BN_CTX_new() and so is
	 * trying to reset it for use. Nothing else makes sense, least of all
	 * binary compatibility from a time when they could declare a static
	 * variable. */
	BN_POOL_reset(&ctx->pool);
	BN_STACK_reset(&ctx->stack);
	ctx->used = 0;
	ctx->err_stack = 0;
	ctx->too_many = 0;
}
#endif

BN_CTX *
BN_CTX_new(void)
{
	BN_CTX *ret = malloc(sizeof(BN_CTX));
	if (!ret) {
		BNerror(ERR_R_MALLOC_FAILURE);
		return NULL;
	}

	/* Initialise the structure */
	BN_POOL_init(&ret->pool);
	BN_STACK_init(&ret->stack);
	ret->used = 0;
	ret->err_stack = 0;
	ret->too_many = 0;
	return ret;
}

void
BN_CTX_free(BN_CTX *ctx)
{
	if (ctx == NULL)
		return;
#ifdef BN_CTX_DEBUG
	{
		BN_POOL_ITEM *pool = ctx->pool.head;
		fprintf(stderr, "BN_CTX_free, stack-size=%d, pool-bignums=%d\n",
		    ctx->stack.size, ctx->pool.size);
		fprintf(stderr, "dmaxs: ");
		while (pool) {
			unsigned loop = 0;
			while (loop < BN_CTX_POOL_SIZE)
				fprintf(stderr, "%02x ",
				    pool->vals[loop++].dmax);
			pool = pool->next;
		}
		fprintf(stderr, "\n");
	}
#endif
	BN_STACK_finish(&ctx->stack);
	BN_POOL_finish(&ctx->pool);
	free(ctx);
}

void
BN_CTX_start(BN_CTX *ctx)
{
	CTXDBG_ENTRY("BN_CTX_start", ctx);

	/* If we're already overflowing ... */
	if (ctx->err_stack || ctx->too_many)
		ctx->err_stack++;
	/* (Try to) get a new frame pointer */
	else if (!BN_STACK_push(&ctx->stack, ctx->used)) {
		BNerror(BN_R_TOO_MANY_TEMPORARY_VARIABLES);
		ctx->err_stack++;
	}
	CTXDBG_EXIT(ctx);
}

void
BN_CTX_end(BN_CTX *ctx)
{
	CTXDBG_ENTRY("BN_CTX_end", ctx);

	if (ctx->err_stack)
		ctx->err_stack--;
	else {
		unsigned int fp = BN_STACK_pop(&ctx->stack);
		/* Does this stack frame have anything to release? */
		if (fp < ctx->used)
			BN_POOL_release(&ctx->pool, ctx->used - fp);
		ctx->used = fp;
		/* Unjam "too_many" in case "get" had failed */
		ctx->too_many = 0;
	}
	CTXDBG_EXIT(ctx);
}

BIGNUM *
BN_CTX_get(BN_CTX *ctx)
{
	BIGNUM *ret;

	CTXDBG_ENTRY("BN_CTX_get", ctx);

	if (ctx->err_stack || ctx->too_many)
		return NULL;
	if ((ret = BN_POOL_get(&ctx->pool)) == NULL) {
		/* Setting too_many prevents repeated "get" attempts from
		 * cluttering the error stack. */
		ctx->too_many = 1;
		BNerror(BN_R_TOO_MANY_TEMPORARY_VARIABLES);
		return NULL;
	}
	/* OK, make sure the returned bignum is "zero" */
	BN_zero(ret);
	ctx->used++;
	CTXDBG_RET(ctx, ret);
	return ret;
}

/************/
/* BN_STACK */
/************/

static void
BN_STACK_init(BN_STACK *st)
{
	st->indexes = NULL;
	st->depth = st->size = 0;
}

static void
BN_STACK_finish(BN_STACK *st)
{
	if (st->size)
		free(st->indexes);
}

#ifndef OPENSSL_NO_DEPRECATED
static void
BN_STACK_reset(BN_STACK *st)
{
	st->depth = 0;
}
#endif

static int
BN_STACK_push(BN_STACK *st, unsigned int idx)
{
	if (st->depth == st->size)
		/* Need to expand */
	{
		unsigned int newsize = (st->size ?
		    (st->size * 3 / 2) : BN_CTX_START_FRAMES);
		unsigned int *newitems = reallocarray(NULL,
		    newsize, sizeof(unsigned int));
		if (!newitems)
			return 0;
		if (st->depth)
			memcpy(newitems, st->indexes, st->depth *
			    sizeof(unsigned int));
		if (st->size)
			free(st->indexes);
		st->indexes = newitems;
		st->size = newsize;
	}
	st->indexes[(st->depth)++] = idx;
	return 1;
}

static unsigned int
BN_STACK_pop(BN_STACK *st)
{
	return st->indexes[--(st->depth)];
}

/***********/
/* BN_POOL */
/***********/

static void
BN_POOL_init(BN_POOL *p)
{
	p->head = p->current = p->tail = NULL;
	p->used = p->size = 0;
}

static void
BN_POOL_finish(BN_POOL *p)
{
	while (p->head) {
		unsigned int loop = 0;
		BIGNUM *bn = p->head->vals;
		while (loop++ < BN_CTX_POOL_SIZE) {
			if (bn->d)
				BN_clear_free(bn);
			bn++;
		}
		p->current = p->head->next;
		free(p->head);
		p->head = p->current;
	}
}

#ifndef OPENSSL_NO_DEPRECATED
static void
BN_POOL_reset(BN_POOL *p)
{
	BN_POOL_ITEM *item = p->head;
	while (item) {
		unsigned int loop = 0;
		BIGNUM *bn = item->vals;
		while (loop++ < BN_CTX_POOL_SIZE) {
			if (bn->d)
				BN_clear(bn);
			bn++;
		}
		item = item->next;
	}
	p->current = p->head;
	p->used = 0;
}
#endif

static BIGNUM *
BN_POOL_get(BN_POOL *p)
{
	if (p->used == p->size) {
		BIGNUM *bn;
		unsigned int loop = 0;
		BN_POOL_ITEM *item = malloc(sizeof(BN_POOL_ITEM));
		if (!item)
			return NULL;
		/* Initialise the structure */
		bn = item->vals;
		while (loop++ < BN_CTX_POOL_SIZE)
			BN_init(bn++);
		item->prev = p->tail;
		item->next = NULL;
		/* Link it in */
		if (!p->head)
			p->head = p->current = p->tail = item;
		else {
			p->tail->next = item;
			p->tail = item;
			p->current = item;
		}
		p->size += BN_CTX_POOL_SIZE;
		p->used++;
		/* Return the first bignum from the new pool */
		return item->vals;
	}
	if (!p->used)
		p->current = p->head;
	else if ((p->used % BN_CTX_POOL_SIZE) == 0)
		p->current = p->current->next;
	return p->current->vals + ((p->used++) % BN_CTX_POOL_SIZE);
}

static void
BN_POOL_release(BN_POOL *p, unsigned int num)
{
	unsigned int offset = (p->used - 1) % BN_CTX_POOL_SIZE;

	p->used -= num;
	while (num--) {
		bn_check_top(p->current->vals + offset);
		if (!offset) {
			offset = BN_CTX_POOL_SIZE - 1;
			p->current = p->current->prev;
		} else
			offset--;
	}
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: bn_ctx.c,v 1.15 2017/01/29 17:49:22 beck Exp $ */
2			/* Written by Ulf Moeller for the OpenSSL project. */
3			/* ====================================================================
4			* Copyright (c) 1998-2004 The OpenSSL Project. All rights reserved.
5			*
6			* Redistribution and use in source and binary forms, with or without
7			* modification, are permitted provided that the following conditions
8			* are met:
9			*
10			* 1. Redistributions of source code must retain the above copyright
11			* notice, this list of conditions and the following disclaimer.
12			*
13			* 2. Redistributions in binary form must reproduce the above copyright
14			* notice, this list of conditions and the following disclaimer in
15			* the documentation and/or other materials provided with the
16			* distribution.
17			*
18			* 3. All advertising materials mentioning features or use of this
19			* software must display the following acknowledgment:
20			* "This product includes software developed by the OpenSSL Project
21			* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
22			*
23			* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
24			* endorse or promote products derived from this software without
25			* prior written permission. For written permission, please contact
26			* openssl-core@openssl.org.
27			*
28			* 5. Products derived from this software may not be called "OpenSSL"
29			* nor may "OpenSSL" appear in their names without prior written
30			* permission of the OpenSSL Project.
31			*
32			* 6. Redistributions of any form whatsoever must retain the following
33			* acknowledgment:
34			* "This product includes software developed by the OpenSSL Project
35			* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
36			*
37			* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
38			* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40			* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
41			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
43			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
44			* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
46			* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
47			* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
48			* OF THE POSSIBILITY OF SUCH DAMAGE.
49			* ====================================================================
50			*
51			* This product includes cryptographic software written by Eric Young
52			* (eay@cryptsoft.com). This product includes software written by Tim
53			* Hudson (tjh@cryptsoft.com).
54			*
55			*/
56
57			#if !defined(BN_CTX_DEBUG) && !defined(BN_DEBUG)
58			#ifndef NDEBUG
59			#define NDEBUG
60			#endif
61			#endif
62
63			#include <stdio.h>
64			#include <string.h>
65
66			#include <openssl/opensslconf.h>
67
68			#include <openssl/err.h>
69
70			#include "bn_lcl.h"
71
72			/* TODO list
73			*
74			* 1. Check a bunch of "(words+1)" type hacks in various bignum functions and
75			* check they can be safely removed.
76			* - Check +1 and other ugliness in BN_from_montgomery()
77			*
78			* 2. Consider allowing a BN_new_ex() that, at least, lets you specify an
79			* appropriate 'block' size that will be honoured by bn_expand_internal() to
80			* prevent piddly little reallocations. OTOH, profiling bignum expansions in
81			* BN_CTX doesn't show this to be a big issue.
82			*/
83
84			/* How many bignums are in each "pool item"; */
85			#define BN_CTX_POOL_SIZE 16
86			/* The stack frame info is resizing, set a first-time expansion size; */
87			#define BN_CTX_START_FRAMES 32
88
89			/***********/
90			/* BN_POOL */
91			/***********/
92
93			/* A bundle of bignums that can be linked with other bundles */
94			typedef struct bignum_pool_item {
95			/* The bignum values */
96			BIGNUM vals[BN_CTX_POOL_SIZE];
97			/* Linked-list admin */
98			struct bignum_pool_item prev, next;
99			} BN_POOL_ITEM;
100
101			/* A linked-list of bignums grouped in bundles */
102			typedef struct bignum_pool {
103			/* Linked-list admin */
104			BN_POOL_ITEM head, current, *tail;
105			/* Stack depth and allocation size */
106			unsigned used, size;
107			} BN_POOL;
108
109			static void BN_POOL_init(BN_POOL *);
110			static void BN_POOL_finish(BN_POOL *);
111			#ifndef OPENSSL_NO_DEPRECATED
112			static void BN_POOL_reset(BN_POOL *);
113			#endif
114			static BIGNUM * BN_POOL_get(BN_POOL *);
115			static void BN_POOL_release(BN_POOL *, unsigned int);
116
117			/************/
118			/* BN_STACK */
119			/************/
120
121			/* A wrapper to manage the "stack frames" */
122			typedef struct bignum_ctx_stack {
123			/* Array of indexes into the bignum stack */
124			unsigned int *indexes;
125			/* Number of stack frames, and the size of the allocated array */
126			unsigned int depth, size;
127			} BN_STACK;
128
129			static void BN_STACK_init(BN_STACK *);
130			static void BN_STACK_finish(BN_STACK *);
131			#ifndef OPENSSL_NO_DEPRECATED
132			static void BN_STACK_reset(BN_STACK *);
133			#endif
134			static int BN_STACK_push(BN_STACK *, unsigned int);
135			static unsigned int BN_STACK_pop(BN_STACK *);
136
137			/**********/
138			/* BN_CTX */
139			/**********/
140
141			/* The opaque BN_CTX type */
142			struct bignum_ctx {
143			/* The bignum bundles */
144			BN_POOL pool;
145			/* The "stack frames", if you will */
146			BN_STACK stack;
147			/* The number of bignums currently assigned */
148			unsigned int used;
149			/* Depth of stack overflow */
150			int err_stack;
151			/* Block "gets" until an "end" (compatibility behaviour) */
152			int too_many;
153			};
154
155			/* Enable this to find BN_CTX bugs */
156			#ifdef BN_CTX_DEBUG
157			static const char *ctxdbg_cur = NULL;
158
159			static void
160			ctxdbg(BN_CTX *ctx)
161			{
162			unsigned int bnidx = 0, fpidx = 0;
163			BN_POOL_ITEM *item = ctx->pool.head;
164			BN_STACK *stack = &ctx->stack;
165
166			fprintf(stderr, "(%08x): ", (unsigned int)ctx);
167			while (bnidx < ctx->used) {
168			fprintf(stderr, "%03x ",
169			item->vals[bnidx++ % BN_CTX_POOL_SIZE].dmax);
170			if (!(bnidx % BN_CTX_POOL_SIZE))
171			item = item->next;
172			}
173			fprintf(stderr, "\n");
174			bnidx = 0;
175			fprintf(stderr, " : ");
176			while (fpidx < stack->depth) {
177			while (bnidx++ < stack->indexes[fpidx])
178			fprintf(stderr, " ");
179			fprintf(stderr, "^^^ ");
180			bnidx++;
181			fpidx++;
182			}
183			fprintf(stderr, "\n");
184			}
185			#define CTXDBG_ENTRY(str, ctx) \
186			do { \
187			ctxdbg_cur = (str); \
188			fprintf(stderr, "Starting %s\n", ctxdbg_cur); \
189			ctxdbg(ctx); \
190			} while(0)
191
192			#define CTXDBG_EXIT(ctx) \
193			do { \
194			fprintf(stderr, "Ending %s\n", ctxdbg_cur); \
195			ctxdbg(ctx); \
196			} while(0)
197
198			#define CTXDBG_RET(ctx,ret)
199			#else
200			#define CTXDBG_ENTRY(str, ctx)
201			#define CTXDBG_EXIT(ctx)
202			#define CTXDBG_RET(ctx,ret)
203			#endif
204
205			/* This function is an evil legacy and should not be used. This implementation
206			* is WYSIWYG, though I've done my best. */
207			#ifndef OPENSSL_NO_DEPRECATED
208			void
209			BN_CTX_init(BN_CTX *ctx)
210			{
211			/* Assume the caller obtained the context via BN_CTX_new() and so is
212			* trying to reset it for use. Nothing else makes sense, least of all
213			* binary compatibility from a time when they could declare a static
214			* variable. */
215			BN_POOL_reset(&ctx->pool);
216			BN_STACK_reset(&ctx->stack);
217			ctx->used = 0;
218			ctx->err_stack = 0;
219			ctx->too_many = 0;
220			}
221			#endif
222
223			BN_CTX *
224			BN_CTX_new(void)
225			{
226		863442	BN_CTX *ret = malloc(sizeof(BN_CTX));
227	✗✓	431721	if (!ret) {
228			BNerror(ERR_R_MALLOC_FAILURE);
229			return NULL;
230			}
231
232			/* Initialise the structure */
233		431721	BN_POOL_init(&ret->pool);
234		431721	BN_STACK_init(&ret->stack);
235		431721	ret->used = 0;
236		431721	ret->err_stack = 0;
237		431721	ret->too_many = 0;
238		431721	return ret;
239		431721	}
240
241			void
242			BN_CTX_free(BN_CTX *ctx)
243			{
244	✓✓	4972704	if (ctx == NULL)
245			return;
246			#ifdef BN_CTX_DEBUG
247			{
248			BN_POOL_ITEM *pool = ctx->pool.head;
249			fprintf(stderr, "BN_CTX_free, stack-size=%d, pool-bignums=%d\n",
250			ctx->stack.size, ctx->pool.size);
251			fprintf(stderr, "dmaxs: ");
252			while (pool) {
253			unsigned loop = 0;
254			while (loop < BN_CTX_POOL_SIZE)
255			fprintf(stderr, "%02x ",
256			pool->vals[loop++].dmax);
257			pool = pool->next;
258			}
259			fprintf(stderr, "\n");
260			}
261			#endif
262		431721	BN_STACK_finish(&ctx->stack);
263		431721	BN_POOL_finish(&ctx->pool);
264		431721	free(ctx);
265		2918073	}
266
267			void
268			BN_CTX_start(BN_CTX *ctx)
269			{
270			CTXDBG_ENTRY("BN_CTX_start", ctx);
271
272			/* If we're already overflowing ... */
273	✓✗✗✓	119079903	if (ctx->err_stack \|\| ctx->too_many)
274			ctx->err_stack++;
275			/* (Try to) get a new frame pointer */
276	✗✓	39693301	else if (!BN_STACK_push(&ctx->stack, ctx->used)) {
277			BNerror(BN_R_TOO_MANY_TEMPORARY_VARIABLES);
278			ctx->err_stack++;
279			}
280			CTXDBG_EXIT(ctx);
281		39693301	}
282
283			void
284			BN_CTX_end(BN_CTX *ctx)
285			{
286			CTXDBG_ENTRY("BN_CTX_end", ctx);
287
288	✗✓	79386592	if (ctx->err_stack)
289			ctx->err_stack--;
290			else {
291		39693296	unsigned int fp = BN_STACK_pop(&ctx->stack);
292			/* Does this stack frame have anything to release? */
293	✓✓	39693296	if (fp < ctx->used)
294		31863774	BN_POOL_release(&ctx->pool, ctx->used - fp);
295		39693296	ctx->used = fp;
296			/* Unjam "too_many" in case "get" had failed */
297		39693296	ctx->too_many = 0;
298			}
299			CTXDBG_EXIT(ctx);
300		39693296	}
301
302			BIGNUM *
303			BN_CTX_get(BN_CTX *ctx)
304			{
305			BIGNUM *ret;
306
307			CTXDBG_ENTRY("BN_CTX_get", ctx);
308
309	✓✗✗✓	166754946	if (ctx->err_stack \|\| ctx->too_many)
310			return NULL;
311	✗✓	55584982	if ((ret = BN_POOL_get(&ctx->pool)) == NULL) {
312			/* Setting too_many prevents repeated "get" attempts from
313			* cluttering the error stack. */
314			ctx->too_many = 1;
315			BNerror(BN_R_TOO_MANY_TEMPORARY_VARIABLES);
316			return NULL;
317			}
318			/* OK, make sure the returned bignum is "zero" */
319		55584982	BN_zero(ret);
320		55584982	ctx->used++;
321			CTXDBG_RET(ctx, ret);
322		55584982	return ret;
323		55584982	}
324
325			/************/
326			/* BN_STACK */
327			/************/
328
329			static void
330			BN_STACK_init(BN_STACK *st)
331			{
332		863442	st->indexes = NULL;
333		431721	st->depth = st->size = 0;
334		431721	}
335
336			static void
337			BN_STACK_finish(BN_STACK *st)
338			{
339	✓✓	863442	if (st->size)
340		428959	free(st->indexes);
341		431721	}
342
343			#ifndef OPENSSL_NO_DEPRECATED
344			static void
345			BN_STACK_reset(BN_STACK *st)
346			{
347			st->depth = 0;
348			}
349			#endif
350
351			static int
352			BN_STACK_push(BN_STACK *st, unsigned int idx)
353			{
354	✓✓	79386602	if (st->depth == st->size)
355			/* Need to expand */
356			{
357	✗✓	857918	unsigned int newsize = (st->size ?
358			(st->size * 3 / 2) : BN_CTX_START_FRAMES);
359		428959	unsigned int *newitems = reallocarray(NULL,
360		428959	newsize, sizeof(unsigned int));
361	✗✓	428959	if (!newitems)
362			return 0;
363	✗✓	428959	if (st->depth)
364			memcpy(newitems, st->indexes, st->depth *
365			sizeof(unsigned int));
366	✗✓	428959	if (st->size)
367			free(st->indexes);
368		428959	st->indexes = newitems;
369		428959	st->size = newsize;
370	✓✗	428959	}
371		39693301	st->indexes[(st->depth)++] = idx;
372		39693301	return 1;
373		39693301	}
374
375			static unsigned int
376			BN_STACK_pop(BN_STACK *st)
377			{
378		79386592	return st->indexes[--(st->depth)];
379			}
380
381			/***********/
382			/* BN_POOL */
383			/***********/
384
385			static void
386			BN_POOL_init(BN_POOL *p)
387			{
388		863442	p->head = p->current = p->tail = NULL;
389		431721	p->used = p->size = 0;
390		431721	}
391
392			static void
393			BN_POOL_finish(BN_POOL *p)
394			{
395	✓✓	2142623	while (p->head) {
396			unsigned int loop = 0;
397		423730	BIGNUM *bn = p->head->vals;
398	✓✓	14406820	while (loop++ < BN_CTX_POOL_SIZE) {
399	✓✓	6779680	if (bn->d)
400		1584471	BN_clear_free(bn);
401		6779680	bn++;
402			}
403		423730	p->current = p->head->next;
404		423730	free(p->head);
405		423730	p->head = p->current;
406			}
407		431721	}
408
409			#ifndef OPENSSL_NO_DEPRECATED
410			static void
411			BN_POOL_reset(BN_POOL *p)
412			{
413			BN_POOL_ITEM *item = p->head;
414			while (item) {
415			unsigned int loop = 0;
416			BIGNUM *bn = item->vals;
417			while (loop++ < BN_CTX_POOL_SIZE) {
418			if (bn->d)
419			BN_clear(bn);
420			bn++;
421			}
422			item = item->next;
423			}
424			p->current = p->head;
425			p->used = 0;
426			}
427			#endif
428
429			static BIGNUM *
430			BN_POOL_get(BN_POOL *p)
431			{
432	✓✓	111169964	if (p->used == p->size) {
433			BIGNUM *bn;
434			unsigned int loop = 0;
435		423730	BN_POOL_ITEM *item = malloc(sizeof(BN_POOL_ITEM));
436	✗✓	423730	if (!item)
437			return NULL;
438			/* Initialise the structure */
439		423730	bn = item->vals;
440	✓✓	14406820	while (loop++ < BN_CTX_POOL_SIZE)
441		6779680	BN_init(bn++);
442		423730	item->prev = p->tail;
443		423730	item->next = NULL;
444			/* Link it in */
445	✓✓	423730	if (!p->head)
446		420923	p->head = p->current = p->tail = item;
447			else {
448		2807	p->tail->next = item;
449		2807	p->tail = item;
450		2807	p->current = item;
451			}
452		423730	p->size += BN_CTX_POOL_SIZE;
453		423730	p->used++;
454			/* Return the first bignum from the new pool */
455		423730	return item->vals;
456			}
457	✓✓	55161252	if (!p->used)
458		1240390	p->current = p->head;
459	✓✓	53920862	else if ((p->used % BN_CTX_POOL_SIZE) == 0)
460		435525	p->current = p->current->next;
461		56837167	return p->current->vals + ((p->used++) % BN_CTX_POOL_SIZE);
462		55584982	}
463
464			static void
465			BN_POOL_release(BN_POOL *p, unsigned int num)
466			{
467		63727548	unsigned int offset = (p->used - 1) % BN_CTX_POOL_SIZE;
468
469		31863774	p->used -= num;
470	✓✓	119312498	while (num--) {
471			bn_check_top(p->current->vals + offset);
472	✓✓	55584950	if (!offset) {
473			offset = BN_CTX_POOL_SIZE - 1;
474		2099636	p->current = p->current->prev;
475		2099636	} else
476		53485314	offset--;
477			}
478		31863774	}